Clean Indoor Air Laws, Cigarette Taxes, and Use of Smoking Cessation Treatments Smoking is the leading cause of preventable death in the U.S., and 42 million U.S. adults are smokers. While 70-85% of smokers who quit do so without treatment, studies confirm that treatment is effective and helps individuals remain abstinent. Over-the-counter and prescription treatments and counseling services are available to assist the nearly 70% of smokers who want to quit. As of 2014, the Patient Protection and Affordable Care Act (ACA) grants many Americans greater access to cessation treatments. While this unprecedented coverage improves treatments' availability, it does not address utilization. In other words, coverage of cessation treatments will have little effect unless smokers actually use them. Yet, not much is known about what drives smokers to use these treatments. Because states and localities have limited funds to spend on tobacco control, these sub-national jurisdictions can augment their tobacco control efforts via low- cost policy changes. If policies such as clean indoor air laws and higher tobacco taxes increase smoking cessation by promoting cessation treatment use, states and localities could capitalize on the ACA's coverage of cessation treatments to increase cessation by enacting or strengthening their own policies. Virtually no studies have investigated whether state and local tobacco control policies are associated with increased use of cessation treatments. The proposed study would provide this critical information at an auspicious time, given that the ACA is dramatically increasing the availability of cessation treatment. We propose to use data on state and local tobacco control laws and data from the Current Population Survey-Tobacco Use Supplements (CPS-TUS) to determine the extent to which state and local clean indoor air laws and cigarette taxes might increase rates of cessation by promoting cessation-related health service use, and whether this differs across specific population sub-groups. We propose to: 1) examine the association of state and local clean indoor air laws and cigarette taxes with smoking cessation and treatment use in 2002/2003 and again in 2010/2011; 2) examine whether use of cessation treatment mediates the association of state and local clean indoor air laws and cigarette taxes with smoking cessation; and 3) examine differences in the association of state and local clean indoor air laws and cigarette taxes with cessation treatment use among population sub-groups using moderated mediation models. Clean indoor air laws and cigarette taxes are among a small number of low-cost, population-level interventions that may drive use of cessation treatments. For states and localities lacking clean indoor air laws or with lower cigarette taxes, findings may encourage the creation or strengthening of these laws to promote treatment use and cessation, capitalizing on the ACA's cessation treatment coverage. Findings may also encourage states with more comprehensive clean indoor air laws and higher cigarette taxes to more broadly cover cessation services under Medicaid, beyond the ACA requirements, to augment their tobacco control laws' effects.